title: Controlled meal frequency without caloric restriction alters peripheral blood mononuclear cell cytokine production.
abstract: BACKGROUND
  Intermittent fasting (IF) improves healthy lifespan in animals by a mechanism involving reduced oxidative damage and increased resistance to stress. However, no studies have evaluated the impact of controlled meal frequency on immune responses in human subjects.
  
  
  OBJECTIVE
  A study was conducted to establish the effects of controlled diets with different meal frequencies, but similar daily energy intakes, on cytokine production in healthy male and female subjects.
  
  
  METHODS
  In a crossover study design with an intervening washout period, healthy normal weight middle-age male and female subjects (n = 15) were maintained for 2 months on controlled on-site one meal per day (OMD) or three meals per day (TMD) isocaloric diets. Serum samples and peripheral blood mononuclear cells (PBMCs) culture supernatants from subjects were analyzed for the presence of inflammatory markers using a multiplex assay.
  
  
  RESULTS
  There were no significant differences in the inflammatory markers in the serum of subjects on the OMD or TMD diets. There was an increase in the capacity of PBMCs to produce cytokines in subjects during the first month on the OMD or TMD diets.Lower levels of TNF-α, IL-17, MCP-1 and MIP-1β were produced by PBMCs from subjects on the OMD versus TMD diet.
  
  
  CONCLUSIONS
  PBMCs of subjects on controlled diets exhibit hypersensitivities to cellular stimulation suggesting that stress associated with altered eating behavior might affect cytokine production by immune cells upon stimulation. Moreover, stimulated PBMCs derived from healthy individuals on a reduced meal frequency diet respond with a reduced capability to produce cytokines.
authors.affiliation: Laboratory of Molecular Biology and Immunology, National Institute on Aging, National Institutes of Health, (251 Bayview Boulevard), Baltimore, MD, (21224), USA. taubd@grc.nia.nih.gov.
authors.forename: Vishwa Deep
authors.initials: VD
authors.lastname: Dixit
authors.forename: Hyunwon
authors.initials: H
authors.lastname: Yang
authors.forename: Khaleel S
authors.initials: KS
authors.lastname: Sayeed
authors.forename: Kim S
authors.initials: KS
authors.lastname: Stote
authors.forename: William V
authors.initials: WV
authors.lastname: Rumpler
authors.forename: David J
authors.initials: DJ
authors.lastname: Baer
authors.forename: Dan L
authors.initials: DL
authors.lastname: Longo
authors.forename: Mark P
authors.initials: MP
authors.lastname: Mattson
authors.forename: Dennis D
authors.initials: DD
authors.lastname: Taub